Section 191A(1) is a discretionary power. Consequently, it is necessary to have regard to all relevant factors, in order to decide whether (on the balance of probabilities) there is sufficient reason to make the rectification.

Matters that can be relevant are:

Is there an error in the Register
The purpose of the rectification
Delays in making the rectification
The consequences of making the rectification
Whether there has been a disclosure of all relevant matters

Is there an error in the Register?

Section 191A(1) is predicated on the existence of an error or omission in the Register. Consequently, the Commissioner will need to be satisfied that:

i. the Register is in error, and

ii. the alteration will rectify that error.

It is the responsibility of the patentee to establish these basic facts.

Where the patentee cannot establish, on the balance of probabilities, that there is an error in the Register, and that the alteration would rectify that error, then the Commissioner will not make the alteration.

For instance, if the patentee requests a change in the inventor listed on the Register, but it is uncertain who is the actual inventor, then it is neither clear that the Register is in error, nor that the alteration is a rectification.

A declaration will usually be necessary to satisfy the Commissioner that there has been an error. However, where the error is self-evident, such as where an alteration to the title is sought and the former title is clearly inadequate, extensive evidence will not be required.

The purpose of the rectification

Where the error in the Register arose unintentionally, and as a result of an accidental error by the patentee or the Commissioner, that is a consideration that lies in favour of allowing the rectification.

In this regard, the concept of an error or omission developed in relation to section 223 is relevant. The decision of Jenkinson J in Kimberly-Clark Ltd v Commissioner of Patents (No 3) 13 IPR 569 provides useful guidance:

"the word 'error' is not easily assigned a clear meaning restricted by reference to one or several particular categories of flawed mental function. The attempt is likely to lead to the drawing of fine and often unrealistic distinctions. And some errors of judgement by agents and attorneys may be as bizarre and as little to be anticipated as lapses of memory and accidental slip. …"

"By no means every judgement … which can be shown to have been mistaken will answer the description "error or omission" in the ordinary meaning of those words"

On the other hand, where the error in the Register was the consequence of a deliberate decision, and there has been a subsequent change of mind, that is a consideration that lies against allowing the rectification.

Delay in correcting the error

The Register is a publicly available record of important information in relation to patents. Consequently, it is not in the public interest for the Register to be inaccurate, or for it to remain inaccurate for any longer than is necessary.

Errors in the Register generally arise from the provision of inaccurate information by the patentee either at filing of the application or during prosecution. The period between the provision of the inaccurate information (or the omission to provide relevant information) and the rectification of the Register needs to be explained and considered.

It is particularly important to consider the length of time between discovering the error in the Register and seeking rectification. Consequently, it is expected that where such a delay has occurred an explanation in declaratory form will be provided.

Consequence of the alteration

Some changes to the Register have significant consequences. For instance, the addition of a priority claim may convert an invalid patent into a valid patent - which could significantly affect the public.

Where the rectification of the Register is likely to have a significant impact on third parties, that is a consideration that lies against allowing the rectification.

In other instances an alteration could be inconsistent with other provisions of the Act or Regulations. For instance, it would be inappropriate to alter the Register to include a claim to divisional status where the parent case was lapsed at the time of filing the present patent, since the claim to divisional status would be invalid.

Another example would be the inclusion of a basic document that was filed more than 12 months before the filing date of the present patent. Since the priority claim could not be valid, it would be inappropriate to alter the Register to include an invalid priority claim.

Additionally, in a situation where an alteration would remove a patent of addition status, it is likely that the patent would immediately become invalid as lacking inventive step in the light of the "parent" patent. It would be inappropriate to allow such an alteration.

Has there been a disclosure of all relevant considerations?

Finally, it is incumbent on a patentee to disclose all relevant matters relating to the error or omission in the Register. Where a patentee fails to do so, that lies against allowing the rectification.